CVE-2021-3427Network attack vector

Stored XSS via unencoded torrent attributes

Published Aug 26, 2022 · Updated Aug 3, 2024

Stored XSS in Deluge Web-UI before 2.1.0 allows remote attackers to execute JavaScript in a user's browser via a crafted torrent file. The Web-UI renders attacker-controlled torrent attributes as HTML without encoding HTML entities. Exploitation requires a user to add the malicious torrent and view its attributes in the Web-UI, exposing that browser session to script-driven data access or actions.

CVSS severity5.3
Medium
EPSS probability0.94%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Deluge Web-UI before 2.1.0 allows remote attackers to execute JavaScript in a user's browser via a crafted torrent file. The Web-UI renders attacker-controlled torrent attributes as HTML without encoding HTML entities. Exploitation requires a user to add the malicious torrent and view its attributes in the Web-UI, exposing that browser session to script-driven data access or actions.

The record

CVE
CVE-2021-3427
Published
Aug 26, 2022
Updated
Aug 3, 2024
Vendor
Deluge Project
Product
Deluge
Classifications
CWE-79, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Not-Known

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Deluge Project · Delugeversion=Not-Known

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.3GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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